The present invention relates to a fuel cell system and, more particularly, to a fail-safe technique provided to cope with an abnormality in a gas condition detection means (gas state detector) for detecting a gas condition of a reactive gas.
In a fuel cell vehicle which travels by driving a traction motor by electric power generated in a fuel cell system, the electric power required of the system is computed on the basis of the acceleration opening and the vehicle speed for example, and the rate of supply of reactive gas and the pressure at which reactive gas is supplied are controlled so that the electric power generated in the fuel cell system equals the target electric power. In Japanese Patent Laid-Open No. 2003-168467 is proposed a controller for a fuel cell system for use in a vehicle in which the air pressure at an air pole is controlled at a target pressure by operating at a target rotational speed a compressor for compressing air to be supplied to the air pole and by operating an air pressure control valve. This document discloses a technique to correct a target rotational speed by estimating atmospheric pressure on the basis of operating parameters of a compressor necessary for maintaining the target rotational speed of the compressor or maintaining the air pressure at a target pressure and to limit the amount of electric power generated in a fuel cell by correcting the time period during which a hydrogen package valve is opened.